Increased dopamine receptor sensitivity after estrogen treatment using the rat rotation model.

Estrogen was administered to male rats that had received unilateral injections of 6-hydroxydopamine into the striatum. Following this treatment, their duration of rotation increased in response to amphetamine. Estrogen treatment resulted in a corresponding increase in the number of striatal dopamine receptors. Therefore, both behavioral and biochemical evidence suggests that striatal dopamine function is influenced by peripherally administered estrogens. These results are relevant to the clinical cases of chorea associated with elevated concentrations of estrogen, which occur in pregnancy and during oral contraceptive use.